Electrical stimulation and drug delivery to portions of the anatomy, particularly the spinal anatomy and peripheral nervous system, often involve the implantation of one or more leads or delivery devices within the patient's body. The leads or delivery devices extend between the target anatomy and an implantable pulse generator (IPG) or drug reservoir which is typically implanted at a remote location. Precise positioning of the leads or delivery devices is desired to optimize treatment. Accuracy in administration of the drugs or stimulation to a particular target location can maximize beneficial effects of treatment and patient satisfaction. It is desired that such accuracy be maintained over time to ensure continued successful treatment.
For example, when implanting an epidural lead, a physician must surgically open the body tissue to the epidural space, and then insert the lead into the epidural space to the desired location. Fluoroscopy aids the physician, and trial and error tests of treatment define the desired location(s) for treatment. Once optimally positioned, it is desired to maintain the lead in place. Typically this is attempted by suturing the lead in place, such as by attaching a suture sleeve to the lead and suturing the sleeve to the surrounding tissue where the lead enters the epidural space. In addition, sutures are placed to prevent movement between the sleeve and the lead. The quality of the connection between the sleeve and lead depends on the tightness of the sutures and is highly variable. Such suturing is time consuming, tedious and subject to error. Further, any repositioning requires removal of the sutures and re-suturing. Also, such suturing is dependent on the quality and availability of suitable surrounding tissue and accessibility to the physician.
Unfortunately, leads have been known to move over time due to motion of the surrounding tissue after implantation. Therefore, attempts have been made to anchor the leads to resist migration. For example, when implanting an epidural lead, a physician inserts a lead into the epidural space and then typically sutures the lead to surrounding soft tissue. Pacemaker leads are typically anchored into soft tissue in or near the heart. And percutaneous catheters or peripherally inserted central catheters (PICC) are sutured to the skin outside of the body.
However, these methods are not applicable to minimally invasive procedures where the anchoring sites are not accessible by an open suture technique. In addition, such superficial suturing to soft tissue lacks stability in that soft tissue can stretch over time and during motion which may allow the lead to migrate. Thus, it is desired to provide mechanisms for anchoring leads, catheters and other devices within body tissue that are easy, efficient to use, reliable and allow anchoring in close proximity to the site of stimulation or drug delivery to enhance effectiveness and reduce the potential for migration. At least some of these objectives will be met by the present invention. It is desired to provide mechanisms for anchoring leads, catheters or other devices within body tissue that are easy and efficient to use, reliable, and adjustable. At least some of these objectives will be met by embodiments of the present invention.